body {
    margin: 0;
}
ul , ol {
    padding: 0;
    margin: 0;
    list-style: none;
}
a {
    text-decoration: none;
    color: #000;
}
.swiper-wrapper {
    font-size: 20px;
}

.wrapper-container {
    width: 450px;
    height: 200px;
    background-color: #ccc;
    border: 10px solid #000; 
    /* margin: 100px auto 0; */
    position: relative;
}
.banner {
    width: 450px;
    height: 200px;
    overflow: hidden;
}
.banner ul {
    width: 1800px;
    height: 200px;
    margin-left: 0px;
}
.banner ul li {
    width: 450px;
    height: 200px;
    text-align: center;
    line-height: 200px;
    font-size: 40px;
    font-weight: bold;
    float: left;
}
.banner ul li  a {
    width: 450px;
    height: 200px;
    display: block;
}
.banner ul li a img {
    width: 450px;
    height: 200px;
    vertical-align: middle;
}

/* 用背景色代替图片 */
.banner ul li:nth-child(1) {
    background-color: darkred;
}
.banner ul li:nth-child(2) {
    background-color: lightgreen;
}
.banner ul li:nth-child(3) {
    background-color: deepskyblue;
}
.banner ul li:nth-child(4) {
    background-color: darkred;
}

/* 导航点 */
.point {
    width: 100%;
    height: 20px;
    /* background-color: pink; */
    position: absolute;
    bottom: 0;
    left: 0;
}
.point ol {
    width: 100%;
    height: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
}
.point ol li {
    width: 12px;
    height: 12px;
    background-color: #ffffff;
    border-radius: 50%;
    margin: 0 10px;
    cursor: pointer;
}
.point ol li.active {
    background-color: red;
}

/* 左右按钮 */
.btn-left , .btn-right {
    width: 30px;
    height: 50px;
    background-color: rgba(255,255,255,.1);
    position: absolute;
    top: 50%;
    margin-top: -25px;
    text-align: center;
    line-height: 50px;
}
.btn-left:hover , .btn-right:hover {
    background-color: rgba(255,255,255,.5);
}
.btn-left {
    left: 10px;
}
.btn-right {
    right: 10px;
}

.btn-left .icon ,.btn-right .icon {
    display: inline-block;
    vertical-align: middle;
    width: 20px;
    height: 20px;
    background-size: 20px 20px;
}
.btn-left .icon {
    background-image: url(../icon/left.png);
}
.btn-right .icon {
    background-image: url(../icon/right.png);
}